The Road beyond Lithium Batteries Is Paved—In Three Dimensions—with Zinc

Zinc-based batteries offer a safe, inexpensive, aqueous alternative to fire-prone lithium-based batteries, but do not exhibit sufficient rechargeability — until now. The principal drawbacks associated with zinc, namely inefficient zinc utilization and limited rechargeability, are a consequence of the complex dissolution/precipitation dynamics of zinc in alkaline electrolyte that are further exacerbated in conventional powder composite electrodes. We have redesigned the zinc electrode as a porous, monolithic, three-dimensional (3D) aperiodic architecture (“sponge”); this form is manufacturable and readily scaled in size. When discharged in a primary zinc–air cell, the zinc sponge achieves ~90% of theoretical zinc charge-storage capacity (compared to ~60% in commercial batteries). We further demonstrate that the zinc sponges can be cycled in zinc–vs.–zinc symmetric cells and nickel–zinc and silver–zinc rechargeable cells under conditions that would otherwise lead to short-inducing dendrites with the zinc sponges remaining dendrite-free after extensive cycling to 40% depth-of-discharge relative to full utilization of the zinc (>900 W h/kg[Zn]). Next-generation rechargeable zinc-based batteries are now feasible by using 3D-wired zinc architectures that innately suppress dendrite formation.